ABSTRACT

Pin-fins play a very important role in heat-transfer enhancement in engine combustor liners. In this engineering-scale experimental study, the flow and cooling characteristics of two- and three-layer porous laminates with pin-fins were compared. The influence of the diameter and height of the pin-fin on the flow and cooling characteristics of three-layer porous laminates was also investigated. Adding a third (impingement) layer to the two-layer porous laminate in the study increased the heat-transfer coefficient by 66.00% and the cooling efficiency by 5.90%; both performance factors were further improved as the pin-fin diameter and height in the three-layer laminate were reduced. An empirical expression for the Nusselt number of a three-layer porous laminate was obtained, with a prediction error below 5%.

摘要

针翅片在发动机燃烧室衬里的传热增强中起着非常重要的作用。在这项工程规模的实验研究中，比较了带有针翅的两层和三层多孔层压板的流动和冷却特性。还研究了针翅的直径和高度对三层多孔层压板的流动和冷却特性的影响。在研究中的两层多孔层压板中添加第三层（冲击层）使传热系数提高了 66.00%，冷却效率提高了 5.90%；随着三层层压板中针翅直径和高度的减小，这两个性能因素都得到了进一步的改善。获得了三层多孔层压板的努塞尔数的经验表达式，预测误差低于 5%。